The invention relates to a manoeuvring mode for vehicles with automated clutch.
According to the preamble of claim 1 the invention relates to a manoeuvring mode for vehicles with automated clutch.
In vehicle transmissions constructed without a clutch pedal, for many manoeuvring operations it is desirable to leave the right foot upon the brake pedal which is generally used for giving gas and thus for delivering a reference value signal for the torque in order to be able very quickly brake the vehicle in an emergency should a dangerous torque appear.
EP 0 731 294 A2 has disclosed a manoeuvring mode for vehicles with automated transmissions. There it is proposed, depending on an inching mode selected by the driver, to adapt the gas pedal inclination so as to allow, for a corresponding injection amount, a larger actuating angle than in a different driving mode. The vehicle in this mode can be moved at a lower speed under an equal adjustment angle of the gas pedal. The method has the disadvantage that the driver has to leave his right foot upon the gas pedal for determining the manoeuvring speed. In the event of a dangerous torque, he has to change pedals to be able to brake.
The problem on which this invention is based is to outline a method that allows a quick action upon decelerating devices of the vehicle.
The problem is solved by a method having the features stated in claim 1. Developments are object of sub-claims.
In a method for determining a defined inching procedure of a motor vehicle, the vehicle has an automated clutch with a control device, a gas pedal and a brake pedal, and the vehicle has an actuating element for activating the inching procedure. The time after activation of the inching procedure by the actuating element is measured and compared with a reference value. After exceeding the continues while neither the brake pedal nor the gas pedal is activated. In one embodiment, the activation of the inching procedure is confined to the activated driving steps for the automated forward gear range or the reverse gear range. An elimination of activation of the inching procedure must be avoided especially in the xe2x80x9cparkingxe2x80x9d and xe2x80x9cneutralxe2x80x9d control positions in order not to allow an unintended release of the vehicle movements. One design of the invention allows activation of the inching procedure only in the activated driving steps for the reverse gear range. In one embodiment, the actuating element is controlled by hand, that is, the driver manually engages the actuating element in the area of the control elements for the vehicle which are located in an area accessible to his hands. But in another embodiment, the actuating element is actuated by the foot which does not actuate the brake pedal. One other embodiment provides that a control element, for a function of the vehicle which constitutes an unnecessary function during the inching procedure, can be used as the actuating element so that hereby an additional actuating element can be spared. As control elements for this, for example, a hand lever for actuating an additional brake device such as a retarder or an engine brake switch actuatable by hand or foot are considered. A combined actuation of several switches can also be used for activating the inching procedure.
In an advantageous embodiment, different fixed manoeuvring speeds are preset in the control device which can be called via the actuating element. In one development of the invention, the manoeuvring speed is selected by determining the time of uninterrupted actuation of the actuating element and coordinating a specific manoeuvring speed with a specific time elapsed and, in another embodiment, the manoeuvring speed is selected by determining the number of actuating operations of the actuating element and coordinating a specific manoeuvring speed with a specific number of actuations. In one advantageous development, the idling speed regulator is engaged, for example, via a vehicle master for correcting the idling rotational speed according to engaged auxiliary consumers which otherwise would lower the idling rotational speed and no longer ensure the desired manoeuvring speed.
In the layout of the possible manoeuvring speeds and also of the period during which said speeds can occur, on the basis of the defined clutch differential speed related to the manoeuvring speed, the load capacity of the clutch has to be kept in mind. To this end can serve a limitation of the maximum torque of the clutch or clutch protection functions must be provided in case of overload of the clutch during protracted operation. When using rotational speed sensors of the vehicle whose minimum detectable rotational speed lies below the rotational speeds achieved in the manoeuvring operation. It is also possible to control the manoeuvring operation by the signals about the existing engine torque which can be read from the injection amount and the knowledge, via engaged auxiliary consumers, the same as the differential rotational speed occurring on the clutch.